Improvement in safety-valves



M.SMART 8L T. W. GAYNOR.

Improvement in Safety-Valves'.

vPatented July 30,1872,

v ber A to the engine.

UNITED STATES PATENT OFFICE.

MICHAEL SMART AND THOMAS W. lGrAYNOR, OF NEW YORK, N.k Y.

IMPROVEMENT IN SAFETY-VALVES.

Specification forming part of Letters Patent No. 129,991, dated July 30, 1872.

Specification describing anew and Improved Safety-Valve, invented by MICHAEL SMART andA THoMAs W. GAYNoR, of New York city, in the county and State of 4New York.

The drawing represents a vertical central section of our improved safety-valve.

Similar letters of reference indicate correspondin g parts. v

This invention has for its object to so arrange a safety-valve for steam-boilers that it will be sensitive to the action of the steam, and not liable to become obstructed. This invention consists in providingthe valve-chamber with escape-,steam ports and witha cham-l bered extension, in which is arranged a spiral spring that acts through the medium of a collar and piston-rod to partly hold the piston against the pressure of steam in the boiler, as will be hereinafter described.

A in the drawing represents the valve-chamber, of cylindrical form and secured in avertical position upon a steam-boiler. c is the steampipe leading fromthe lower part of the chamb is the steam-escape pipe projecting from the chamber A at a somewhat greater height than the pipe a.. B is the valve, made inshape of a piston, which fitsthe chamber A with exactness. It is suspended from a stem, d, which is weighted on top.- In an upper chamber, e, through which the stern Id also extends, said stem carries two shoulders, f and g, the lower being fast, the upper loose on it,`and'a coiled spring, h, between the two., The spring h, together with the weight tion top, serves to so far lower the valve that the b, and alsothrough j l b. By screwing down the top m of the chamber e, lowering the loose shoulderf, and contracting the spring h, or by adding to the weight on the top of the stem,

`the valve will be adapted to resist greater' steam-pressure. By making a lan ged opening for the pipe which conveys the steam from the boiler to the engine a part of the safety-valve chamber, we save cutting the usual hole in the boiler for that purpose. l

Having thus described our invention, we claim as new and desire to secure by Letters Patentg Y 1. The valvechamber A provided with the chambered extension e, pipes a b, and parts'j l, all constructed as shown and described, for

the purpose specified.

2. yIn combination with the foregoing, the solid piston B, piston-rod d, collars g s, and spring h, all constructed in the manner and for the purpose specified.

MICHAEL SMART. THOMAS W. GAYNOR.

Witnesses:

T. B. MosHER, W. A. GRAHAM. 

